1. Field of the Invention
The present invention relates to a toner supply apparatus which is installed detachably in an image forming apparatus in a state of accommodating toner.
2. Description of the Related Art
Conventionally, a toner container (toner supply apparatus) is known which supplies toner to a developer apparatus provided inside an image forming apparatus, such as a printer or copying machine. This toner container is attachable and detachable with respect to the image forming apparatus, and when an amount of toner inside the toner container becomes insufficient, a user removes the toner container from the image forming apparatus and replaces it with a new toner container which contains a sufficient amount of toner.
If a toner container filled with toner is left for a long period of time before shipment, toner inside the toner container may clump together (coagulate) due to the pressure created by the toner's own weight. In particular, if the toner container is vertically oriented for a long period of time, then toner in the toner container is inclined to one side inside a long thin container. If a vibration is applied to the toner container during transport, or the like, while in this state, toner becomes very tightly clumped together. Therefore, in order to resolve the coagulated toner, an agitating member which is driven to rotate around an axis is generally provided inside a toner container. The agitating member has a shape where an agitating portion which agitates toner is provided in a projecting fashion toward the outer radial direction from the outer peripheral surface of a rotating axis. By rotating this agitating portion around the rotating axis, the coagulated toner lumps are loosened and agitated.
However, at the start of operation of the agitating member, the agitating portion rotates around the rotating axis while breaking up the coagulated toner lumps, and therefore a large load is applied to the agitating portion and the rotating axis. Consequently, there is a problem in that a large torque is required in order to start the agitating operation.
A toner container which has been improved in order to resolve this problem includes a protective mechanism composed so as to protect the agitating member by shutting off the transmission of drive force to a portion of the agitating member if excessive load is applied to the agitating member at the start of operation of the agitating member.
However, in the improved toner container, an agitating operation is only carried out by a portion of the agitating member in an initial state immediately after installing the toner container in the image forming apparatus. Therefore, sufficient toner cannot be supplied to the developer apparatus until the coagulated toner lumps inside the toner container have been completely broken up, and consequently, the image forming apparatus becomes unable to carry out suitable image forming processes, and there is a possibility of image defects.